Recent Progress in Cs Beam Frequency Standards at the NRLM

Some causes and cures of frequency uncertainty in the cesium beam frequency standard, NRLM-II, are described. Accuracy reevaluation indicates about 2.2 ?? 10-13, and the standard frequency is about 8 ?? 10-14 below that of the International Atomic Time (TAI) scale. The frequency stability is estimated as better than 8 ?? 10-12 ??-1/2 for short-term and 4 ?? 10-14 for 1-2 day averages.